Vocab v31

Density-independent factors

limiting factor that affects all populations in similar ways, regardless of population size e.g. tornado, volcano, meteor, etc.

Mesozoic Era

middle life (245-144 million years ago); rise of mammals and dinosaurs; the rise of birds; extinction of dinosaurs, rise of flowering plants The Mesozoic Era is the age of the dinosaurs and lasted almost 180 million years from approximately 250 to 65 million years ago. This era includes 3 well known periods called the Triassic, Jurassic, and Cretaceous periods. A mass-extinction marked the beginning and end of the Mesozoic Era.

bivalves

mollusks that have two shells held together by hinges and strong muscles an aquatic mollusk that has a compressed body enclosed within a hinged shell, such as oysters, clams, mussels, and scallops. Bivalvia, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts.

biogeochemical cycles

process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another In ecology and Earth science, a biogeochemical cycle or substance turnover or cycling of substances is a pathway by which a chemical substance moves through biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) compartments of Earth.

mycorrhiza

symbiotic association of plant roots and fungi A mycorrhiza is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, its root system. Mycorrhizae play important roles in plant nutrition, soil biology and soil chemistry

beige

tan

Transhumanism

the belief or theory that the human race can evolve beyond its current physical and mental limitations, especially by means of science and technology. humans integrate with technology and upload their brains to the cloud

Eurocentrism

the dominance of European (especially English) cultural patterns

Intermediate Disturbance Hypothesis

the hypothesis that ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels

hydrologic cycle

the movement of water through the biosphere The cycle through which water in the hydrosphere moves; includes such processes as evaporation, precipitation, and surface and groundwater runoff

Fire-stick farming

the practice of Indigenous Australians who regularly used fire to burn vegetation to facilitate hunting and to change the composition of plant and animal species in an area. There are a number of purposes, including to facilitate hunting, to change the composition of plant and animal species in an area, weed control, hazard reduction, and increase of biodiversity. Fire-stick farming had the long-term effect of turning dry forest into savannah, increasing the population of nonspecific grass-eating species like the kangaroo.

composite tools

tools such as bows and arrows in which several different materials are combined (e.g. stone wood, bone, ivory, antler) to produce the final working implement

polygenic

trait controlled by two or more genes

homo erectus

"Upright man" these hominids became skillful hunters and invented more sophisticated tools for digging, scraping and cutting. They also became the first hominids to migrate from Africa. Also were the first to use fire.

australopithecus

"southern ape"; appeared in Africa 4-5 million years ago; stood upright and walked on 2 legs; brain was only 1/3 the size of our brains today Some characteristics: The cranial capacity of the Australopithecus anamensis is unknown. Male height is around 5 feet, while the females are around 4'3". The male weight is around 110 lbs, while the female weight is around 70 lbs.

redact

(v.) - to revise, edit To redact is to arrange or edit text in a written document. Don't get too attached to every word in your rough draft; your teacher will expect you to redact it before handing in your final paper.

"... human population is important to think about because we kinda need to do something about it. And I think pretty much every other species on the planet would agree with me on that." I couldn't agree more. Thanks for pointing out that other species are sharing the Earth with us, it seems that some people disregard that fact when talking about human overpopulation.

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"I am not homophobic. Most definitely homophilic."

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"I wasn't short on connective opportunities, I was just short on connection."

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"Today we will be talking about what happened after the Big Bang." This is quite possibly the vaguest statement possible.

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"We owe our existence to burning gas balls in the sky"

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"biology is all about sex and not dying."

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A photon of light takes only eight minutes to get to the Earth from the surface of the Sun. But it can take 100,000 years from the core of the Sun to get to the surface — where it bursts out and flies at the speed of light.

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All these people trash-talking globalization while on their computers assembled in South Korea, with parts from Japan and manufactured in Taiwan, with minerals for these parts mined in the Congo. While they wear their Chinese clothing, eating South American produce, and their electricity coming from Arab oil. Not to mention, if you're anything other than native-american, your existence in North America is literally a product of globalization. But keep rallying against it because Alex Jones and Breitbart told you it's an Illuminati Soros Podesta conspiracy.

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As stars grow older, their luminosity increases at an appreciable rate. Given the mass of the star, one can use this rate of increase in luminosity in order to determine the age of the star.

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Even more amazing, mantis shrimp strike so quickly that they set the surrounding water boiling. This produces destructive bubbles that quickly collapse, the video showed. As the bubbles collapse, they release energy. This process is called cavitation. While you might think of bubbles as harmless, cavitation can cause serious damage. It can destroy ship propellers, pumps and turbines. With mantis shrimp, researchers think cavitation helps them break apart prey, including snails. Mantis Shrimp: punching so fast that the water around its claws boil and creates minute specs of light is by far the most awesome superpower. This showed mantis shrimp could swing their clubs at speeds of 50 to 83 kilometers (31 to 52 miles) per hour. At the time of the discovery, this was the fastest known strike of any animal. (Scientists have since found insects that strike faster. But these bugs move through air, which is easier to move through than water.)

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Habitat loss is probably the greatest threat to the variety of life on this planet today. It is identified as a main threat to 85% of all species described in the IUCN's Red List (those species officially classified as "Threatened" and "Endangered").

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The microbiome is the genetic material of all the microbes - bacteria, fungi, protozoa and viruses - that live on and inside the human body. The number of genes in all the microbes in one person's microbiome is 200 times the number of genes in the human genome.

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your left hand may have been made in a different star than your right hand.

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Toba catastrophe theory

69,000 and 77,000 years ago, a super volcanic eruption occurred causing a global volcanic winter of 6 to 10 years, reducing human population to 1,000 and 10,000 breeding pairs directly related to us The Toba supereruption was a supervolcanic eruption that occurred about 75,000 years ago at the site of present-day Lake Toba in Sumatra, Indonesia. It is one of the Earth's largest known eruptions. The Toba catastrophe theory holds that this event caused a global volcanic winter of six to ten years and possibly a 1,000-year-long cooling episode.

Cambrian explosion

A burst of evolutionary origins when most of the major body plans of animals appeared in a relatively brief time in geologic history; recorded in the fossil record about 545 to 525 million years ago. These included brachiopods, which lived in shells resembling those of clams or cockles, and animals with jointed, external skeletons known as arthropods—the ancestors of insects, spiders, and crustaceans.

DDT (dichlorodiphenyltrichloroethane)

A colorless odorless water-insoluble crystalline insecticide C14H9Cl5 that tends to accumulate in ecosystems and has toxic effects on many vertebrates; became the most widely used pesticide from WWII to the 1950's; implicated in illnesses and environmental problem; now banned in US. It was originally developed as an insecticide, then it became infamous for its environmental impacts. In experimental animals, such as mice, rats, and dogs, DDT has shown to cause chronic effects on the nervous system, liver, kidneys, and immune system. It has also been found that humans, who were occupationally exposed to DDT, suffered chromosomal damage

potato blight

A destructive fungal disease of potatoes resulting in dry brown rot of the tubers, resulted in Irish Potato Famine Often called potato blight or tomato blight because it particularly affects these crops, it can destroy your entire haul of potatoes in as little as ten days. Blight is a fungal disease caused by spores of Phytophthora infestans which are spread on the wind and which can also contaminate potato tubers in the soil.

homo floresiensis

A distinct species closely related to Homo erectus and only found on the Indonesian island of Flores. They are tiny, with cranial capacities of about 380cc. Nicknamed "Hobbit" for its diminutive size, a possible new species of Homo found in Liang Bua Cave, on the Indonesian island of Flores. Homo floresiensis is an extinct species in the genus Homo. The remains of an individual who would have stood about 1.1 m in height were discovered in 2003 at Liang Bua on the island of Flores in Indonesia. Partial skeletons of nine individuals have been recovered, including one complete skull, referred to as "LB1".

dry docks

A dry dock (sometimes dry-dock or drydock) is a narrow basin or vessel that can be flooded to allow a load to be floated in, then drained to allow that load to come to rest on a dry platform. Dry docks are used for the construction, maintenance, and repair of ships, boats, and other watercraft. Used for maintenance or construction of boats

kink

A kink is a bend or a twist in an otherwise straight line, like a kink in a garden hose that blocks water from flowing freely.

arachnids

A member of a major arthropod group that includes spiders, scorpions, ticks, and mites. All members have eight pairs of walking legs.

Archosaur

A member of the reptilian group that includes crocodiles, alligators and dinosaurs, including birds. Archosaurs are a group of diapsid amniotes and are broadly classified as reptiles. The living representatives of this group consist of birds and crocodilians. This group also includes all extinct dinosaurs, extinct crocodilian relatives, and pterosaurs.

denisovans

A newly discovered group of archaic Homo sapiens from southern Siberia dated to between 30,000 and 50,000 years ago. The nuclear genome from this specimen suggested that Denisovans shared a common origin with Neanderthals, that they ranged from Siberia to Southeast Asia, and that they lived among and interbred with the ancestors of some modern humans, with about three to five percent of the DNA of Melanesians and Aboriginal ...

Kuiper belt

A region of the solar system that is just beyond the orbit of Neptune and that contains small bodies made mostly of ice planetary shrapnel

commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected Examples: Remora fish have a disk on their heads that makes them able to attach to larger animals, such as sharks, mantas, and whales. Nurse plants are larger plants that offer protection to seedlings from the weather and herbivores, giving them an opportunity to grow.

mutualism

A relationship between two species in which both species benefit Mutualism describes the ecological interaction between two or more species where each species has a net benefit. Mutualism is a common type of ecological interaction

Moraine

A ridge formed by the till deposited at the edge of a glacier. a mass of rocks and sediment carried down and deposited by a glacier, typically as ridges at its edges or extremity. A moraine is any glacially formed accumulation of unconsolidated glacial debris that occurs in both currently and formerly glaciated regions on Earth, through geomorphological processes

Batesian mimicry

A type of mimicry in which a harmless species looks like a species that is poisonous or otherwise harmful to predators. An example of Batesian mimicry is the poisonous coral snake and the king snake, which is the mimic. Coral snakes are quite venomous, and their bite is very dangerous to humans and other animals.

gene that codes for earwax

ABCC11 ATP-binding cassette transporter sub-family C member 11 is a protein that in humans is encoded by the ABCC11 gene. The gene is responsible for determination of human cerumen type (wet or dry ear wax) and presence of underarm osmidrosis (odor associated with sweat caused by excessive apocrine secretion).

Antimatter particles share the same mass as their matter counterparts, but qualities such as electric charge are opposite. The positively charged positron, for example, is the antiparticle to the negatively charged electron. Matter and antimatter particles are always produced as a pair and, if they come in contact, annihilate one another, leaving behind pure energy. During the first fractions of a second of the Big Bang, the hot and dense universe was buzzing with particle-antiparticle pairs popping in and out of existence. If matter and antimatter are created and destroyed together, it seems the universe should contain nothing but leftover energy. Nevertheless, a tiny portion of matter - about one particle per billion - managed to survive. This is what we see today. In the past few decades, particle-physics experiments have shown that the laws of nature do not apply equally to matter and antimatter. Physicists are keen to discover the reasons why. Researchers have observed spontaneous transformations between particles and their antiparticles, occurring millions of times per second before they decay. Some unknown entity intervening in this process in the early universe could have caused these "oscillating" particles to decay as matter more often than they decayed as antimatter.

All baryonic matter we have grown to know and love, only constitutes 1/billionth of all the matter that existed after the big bang. For all of the annihilations between matter and antimatter particles, only one in every billion collisions left a particle surviving! Holy frick.

How does more carbon in steel make it stronger?

Although the addition of carbon can provide greater toughness and yield strengths, carbon content of steel itself does not always equate to the alloy's strength. Carbon alloying will make steel more hardenable -- the ability and ease at which the steel alloy can be hardened -- typically by heat treatments or cooling rates. The role of carbon as an interstitial impeding dislocation movement in the steel matrix factors into strength, but carbon's most fundamental and powerful effect with the iron atoms is that it can produce Martensite, a hard, brittle phase that forms when carbon is 'trapped' in the iron crystal lattice. Carbon steel undergoes changes in phases and crystal structure (the way the atoms stack up) with temperature. At temperatures above ~1500F or ~800C, steel is 'Austenitic' and has Face-Centered Cubic (FCC) structure. Below these temperatures it transforms to 'Ferrite' which has Body-Centered Cubic (BCC) structure. When carbon is sitting in between these Fe atoms during the phase change, the Fe atoms will try to rearrange themselves from FCC to BCC, and carbon will diffuse out and form Fe3C, or Cementite. When cooled quickly (water quenched, or even air-cooled for some high-carbon steels), the carbon doesn't have enough time to diffuse out to form Cementite, and Martensite, a Body-Centered Tetragonal (BCT) structure is formed instead of Ferrite which has 0.2 wt% carbon and is actually very soft. Martensite is incredibly brittle because BCT is essentially a sheared state of BCC, and can exhibit a lot of stress within its crystal structure. It is great at impeding slip planes or dislocations within the matrix (what happens when things plastically deform) so much so that it will catastrophically fail rather than deform before ultimate failure, much like ceramics. We can however reduce the brittleness and maintain strength by heat treating the material, or heating up our 'raw' or 'fresh' Martensite to temperatures below the Austenitic temperature (800C) to reintroduce some ductility into our alloy. Steel, by definition is iron containing 0.002 wt% to 2.0 wt% carbon. Iron containing more than 2.0 wt% carbon is either "cast iron" with 2.5 wt% to 3.4 wt% carbon or "pig iron" with 4.2 wt% carbon (4.2 wt % carbon is the solubility limit of carbon in iron). Steel is strong and relatively ductile. Cast iron and pig iron are strong, but brittle. So, if you want steel, don't use too much carbon, or you'll have cast iron or pig iron!

Arthropod

An arthropod is an invertebrate animal having an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Euarthropoda, which includes insects, arachnids, myriapods, and crustaceans. an invertebrate animal of the large phylum Arthropoda, such as an insect, spider, or crustacean.

Primary succession

An ecological succession that begins in an area where no biotic community previously existed Primary succession is one of two types of biological and ecological succession of plant life, occurring in an environment in which new substrate devoid of vegetation and other organisms usually lacking soil, such as a lava flow or area left from retreated glacier, is deposited. No competition!

nitrogenase

An enzyme complex, unique to certain prokaryotes, that reduces N2 to NH3. Only enzyme that can break the triple bond between diatomic nitrogen. Lightning can also break nitrogen apart. Nitrogenases are enzymes that are produced by certain bacteria, such as cyanobacteria. These enzymes are responsible for the reduction of nitrogen to ammonia. Nitrogenases are the only family of enzymes known to catalyze this reaction, which is a key step in the process of nitrogen fixation

Lycophyte

An informal name for a member of the phylum Lycophyta, which includes club mosses, spike mosses, and quillworts. Lycophytes, also known as the 'fern allies', are a clade of vascular plants similar to ferns but have unique leaves called microphylls. They are primitive plants and lack seeds, wood, fruit and flowers

AD, BC, BCE, CE

Anno Domini, Before Christ, Before Common Era, Common Era

Godwin's law

As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches 1

black iron pipe

Black iron pipe is actually made of a low-grade "mild steel" compound. This gives it much better corrosion resistance than traditional cast iron piping. There are few standards that all black iron pipes adhere to. However, they are all made to handle natural and propane gas, which usually stay below 60psi Mild steel contains approximately 0.05-0.30% carbon making it malleable and ductile. Mild steel has a relatively low tensile strength, but it is cheap and easy to form; surface hardness can be increased through carburizing.

How Blood Works

Blood is a mixture of two components: cells and plasma. The heart pumps blood through the arteries, capillaries and veins to provide oxygen and nutrients to every cell of the body. The blood also carries away waste products. The adult human body contains approximately 5 liters (5.3 quarts) of blood; it makes up 7 to 8 percent of a person's body weight. Approximately 2.75 to 3 liters of blood is plasma and the rest is the cellular portion. Plasma is the liquid portion of the blood. Blood cells like red blood cells float in the plasma. Also dissolved in plasma are electrolytes, nutrients and vitamins (absorbed from the intestines or produced by the body), hormones, clotting factors, and proteins such as albumin and immunoglobulins (antibodies to fight infection). Plasma distributes the substances it contains as it circulates throughout the body. The cellular portion of blood contains red blood cells (RBCs), white blood cells (WBCs) and platelets. The RBCs carry oxygen from the lungs; the WBCs help to fight infection; and platelets are parts of cells that the body uses for clotting. All blood cells are produced in the bone marrow. As children, most of our bones produce blood. As we age this gradually diminishes to just the bones of the spine (vertebrae), breastbone (sternum), ribs, pelvis and small parts of the upper arm and leg. Bone marrow that actively produces blood cells is called red marrow, and bone marrow that no longer produces blood cells is called yellow marrow. The process by which the body produces blood is called hematopoiesis. All blood cells (RBCs, WBCs and platelets) come from the same type of cell, called the pluripotential hematopoietic stem cell. This group of cells has the potential to form any of the different types of blood cells and also to reproduce itself. This cell then forms committed stem cells that will form specific types of blood cells. During formation, the RBC eventually loses its nucleus and leaves the bone marrow as a reticulocyte. At this point, the reticulocyte contains some remnants of organelles. Eventually these organelles leave the cell and a mature erythrocyte is formed. RBCs last an average of 120 days in the bloodstream. When RBCs age, they are removed by macrophages in the liver and spleen. A hormone called erythropoietin and low oxygen levels regulate the production of RBCs. Any factor that decreases the oxygen level in the body, such as lung disease or anemia (low number of RBCs), increases the level of erythropoietin in the body. Erythropoietin then stimulates production of RBCs by stimulating the stem cells to produce more RBCs and increasing how quickly they mature. Ninety percent of erythropoietin is made in the kidneys. When both kidneys are removed, or when kidney failure is present, that person becomes anemic due to lack of erythropoietin. Iron, vitamin B-12 and folate are essential in the production of RBCs. Red blood cells (RBCs) are by far the most abundant cells in the blood. RBCs give blood its characteristic red color. In men, there are an average of 5,200,000 RBCs per cubic millimeter (microliter), and in women there are an average of 4,600,000 RBCs per cubic millimeter. RBCs account for approximately 40 to 45 percent of the blood. This percentage of blood made up of RBCs is a frequently measured number and is called the hematocrit. The ratio of cells in normal blood is 600 RBCs for each white blood cell and 40 platelets. There are several things about RBCs that make them unusual: An RBC has a strange shape -- a biconcave disc that is round and flat, sort of like a shallow bowl. An RBC has no nucleus. The nucleus is extruded from the cell as it matures. An RBC can change shape to an amazing extent, without breaking, as it squeezes single file through the capillaries. (Capillaries are minute blood vessels through which oxygen, nutrients and waste products are exchanged throughout the body.) An RBC contains hemoglobin, a molecule specially designed to hold oxygen and carry it to cells that need it. The primary function of red blood cells is to transport oxygen from the lungs to the cells of the body. RBCs contain a protein called hemoglobin that actually carries the oxygen. In the capillaries, the oxygen is released to be used by the cells of the body. Ninety-seven percent of the oxygen that is carried by the blood from the lungs is carried by hemoglobin; the other three percent is dissolved in the plasma. Hemoglobin allows the blood to transport 30 to 100 times more oxygen than could be dissolved in the plasma alone. Hemoglobin combines loosely with oxygen in the lungs, where the oxygen level is high, and then easily releases it in the capillaries, where the oxygen level is low. Each molecule of hemoglobin contains four iron atoms, and each iron atom can bind with one molecule of oxygen (which contains two oxygen atoms, called O2) for a total of four oxygen molecules (4 * O2) or eight atoms of oxygen for each molecule of hemoglobin. The iron in hemoglobin gives blood its red color. Thirty-three percent of an RBC is hemoglobin. The normal concentration of hemoglobin in blood is 15.5 grams per deciliter of blood in men, and 14 grams per deciliter of blood in women. (A deciliter is 100 milliliters, or one-tenth of a liter.) Besides carrying oxygen to the cells of the body, the RBCs help to remove carbon dioxide (CO2) from the body. Carbon dioxide is formed in the cells as a byproduct of many chemical reactions. It enters the blood in the capillaries and is brought back to the lungs and released there and then exhaled as we breathe. RBCs contain an enzyme called carbonic anhydrase which helps the reaction of carbon dioxide (CO2) and water (H2O) to occur 5,000 times faster. Carbonic acid is formed, which then separates into hydrogen ions and bicarbonate ions: Carbonic Anhydrase CO2 + H2O ===> H2CO3 + H+ + HCO3- carbon dioxide + water ==> carbonic acid + hydrogen ion + bicarbonate ion The hydrogen ions then combine with hemoglobin and the bicarbonate ions go into the plasma. Seventy percent of the CO2 is removed in this way. Seven percent of the CO2 is dissolved in the plasma. The remaining 23 percent of the CO2 combines directly with hemoglobin and then is released into the lungs. White blood cells (WBCs), or leukocytes, are a part of the immune system and help our bodies fight infection. They circulate in the blood so that they can be transported to an area where an infection has developed. In a normal adult body there are 4,000 to 10,000 (average 7,000) WBCs per microliter of blood. When the number of WBCs in your blood increases, this is a sign of an infection somewhere in your body. Here are the six main types of WBCs and the average percentage of each type in the blood: Neutrophils - 58 percent Eosinophils - 2 percent Basophils - 1 percent Bands - 3 percent Monocytes - 4 percent Lymphocytes - 4 percent Most WBCs (neutrophils, eosinophils, basophils and monocytes) are formed in the bone marrow. Neutrophils, eosinophils and basophils are also called granulocytes because they have granules in their cells that contain digestive enzymes. Basophils have purple granules, eosinophils have orange-red granules and neutrophils have a faint blue-pink color. When a granulocyte is released into the blood, it stays there for an average of four to eight hours and then goes into the tissues of the body, where it lasts for an average of four to five days. During a severe infection, these times are often shorter. Neutrophils are the one of the body's main defenses against bacteria. They kill bacteria by actually ingesting them (this is called phagocytosis). Neutrophils can phagocytize five to 20 bacteria in their lifetime. Neutrophils have a multi-lobed, segmented or polymorphonuclear nucleus and so are also called PMNs, polys or segs. Bands are immature neutrophils that are seen in the blood. When a bacterial infection is present, an increase of neutrophils and bands are seen. Eosinophils kill parasites and have a role in allergic reactions. Basophils are not well understood, but they function in allergic reactions. They release histamine (which causes blood vessels to leak and attracts WBCs) and heparin (which prevents clotting in the infected area so that the WBCs can reach the bacteria). Monocytes enter the tissue, where they become larger and turn into macrophages. There they can phagocytize bacteria (up to 100 in their lifetime) throughout the body. These cells also destroy old, damaged and dead cells in the body. Macrophages are found in the liver, spleen, lungs, lymph nodes, skin and intestine. The system of macrophages scattered throughout the body is called the reticuloendothelial system. Monocytes stay in the blood for an average of 10 to 20 hours and then go into the tissues, where they become tissue macrophages and can live for months to years. Neutrophils and monocytes use several mechanisms to get to and kill invading organisms. They can squeeze through openings in blood vessels by a process called diapedesis. They move around using ameboid motion. They are attracted to certain chemicals produced by the immune system or by bacteria and migrate toward areas of higher concentrations of these chemicals. This is called chemotaxis. They kill bacteria by a process called phagocytosis, in which they completely surround the bacteria and digest them with digestive enzymes. Lymphocytes are complex cells that direct the body's immune system. T lymphocytes start in the bone marrow from pluripotent hematopoietic stem cells, then travel to and mature in the thymus gland. The thymus is located in the chest between the heart and sternum (breastbone). B lymphocytes mature in the bone marrow. T lymphocytes (T cells) are responsible for cell-mediated immunity. B lymphocytes are responsible for humoral immunity (antibody production). Seventy-five percent of lymphocytes are T cells. Lymphocytes are different from the other WBCs because they can recognize and have a memory of invading bacteria and viruses. Lymphocytes continually pass back and forth between lymph tissue, lymph fluid and blood. When they are present in the blood, they stay for several hours. Lymphocytes can live for weeks, months or years. There are many types of T cells that have specific functions, including: Helper T cells - Helper T cells have proteins on their cell membranes called CD4. Helper T cells direct the rest of the immune system by releasing cytokines. Cytokines stimulate B cells to form plasma cells, which form antibodies, stimulate the production of cytotoxic T cells and suppressor T cells and activate macrophages. Helper T cells are the cells the AIDS virus attacks -- you can imagine that destroying the cells that direct the immune system has a devastating effect. Cytotoxic T cells - Cytotoxic T cells release chemicals that break open and kill invading organisms. Memory T cells - Memory T cells remain afterwards to help the immune system respond more quickly if the same organism is encountered again. Suppressor T cells - Suppressor T cells suppress the immune response so that it does not get out of control and destroy normal cells once the immune response is no longer needed. B cells become plasma cells when exposed to an invading organism or when activated by helper T cells. B cells produce large numbers of antibodies (also called immunoglobulins or gamma globulins). There are five types of immunogloulins (abbreviated Ig): IgG, IgM, IgE, IgA and IgD. These are Y-shaped molecules that have a variable segment that is a binding site for only one specific antigen. These bind to antigens, which causes them to clump, be neutralized or break open. They also activate the complement system. The complement system is a series of enzymes that help or complement antibodies and other components of the immune system to destroy the invading antigen by attracting and activating neutrophils and macrophages, neutralizing viruses and causing invading organisms to break open. Memory B cells also remain for prolonged periods, and if the same antigen is encountered it causes a more rapid response in producing antibodies. Platelets (thrombocytes) help blood to clot by forming something called a platelet plug. The other way that blood clots is through coagulation factors. Platelets also help to promote other blood clotting mechanisms. There are approximately 150,000 to 400,000 platelets in each microliter of blood (average is 250,000). Platelets are formed in the bone marrow from very large cells called megakaryocytes, which break up into fragments -- these cellular fragments are platelets. They do not have a nucleus and do not reproduce. Instead, megakaryocytes produce more platelets when necessary. Platelets generally last for an average of 10 days. Platelets contain many chemicals that assist clotting. These include: Actin and myosin, to help them contract Chemicals that help the coagulation process to begin Chemicals that attract other platelets Chemicals that stimulate blood vessel repair Chemicals that stabilize a blood clot Plasma is a clear, yellowish fluid (the color of straw). Plasma can sometimes appear milky after a very fatty meal or when people have a high level of lipids in their blood. Plasma is 90-percent water. The other 10 percent dissolved in plasma is essential for life. These dissolved substances are circulated throughout the body and diffuse into tissues and cells where they are needed. They diffuse from areas of high concentration to areas of lower concentration. The greater the difference in concentration, the greater the amount of material that diffuses. Waste materials flow in the opposite direction, from where they are created in the cells into the bloodstream, where they are removed either in the kidneys or lungs. Hydrostatic pressure (blood pressure) pushes fluid out of blood vessels. Balancing this is something called oncotic pressure (caused by proteins dissolved in blood), which tends to keep fluid inside the blood vessels. Proteins make up a large part of the 10 percent of material dissolved in plasma and are responsible for oncotic pressure. Protein molecules are much larger than water molecules and tend to stay in blood vessels. They have more difficulty fitting through the pores in capillaries, and therefore have a higher concentration in blood vessels. Proteins tend to attract water to keep their relative concentration in blood vessels more in line with fluid outside the blood vessels. This is one of the ways the body maintains a constant volume of blood. Plasma contains 6.5 to 8.0 grams of protein per deciliter of blood. The main proteins in plasma are albumin (60 percent), globulins (alpha-1, alpha-2, beta, and gamma globulins (immunoglobulins)), and clotting proteins (especially fibrinogen). These proteins function to maintain oncotic pressure (especially albumin) and transport substances such as lipids, hormones, medications, vitamins, and other nutrients. These proteins are also part of the immune system (immunoglobulins), help blood to clot (clotting factors), maintain pH balance, and are enzymes involved in chemical reactions throughout the body. Electrolytes are another large category of substances dissolved in plasma. They include: Sodium (Na+) Potassium (K+) Chloride (Cl-) Bicarbonate (HCO3-) Calcium (Ca+2) Magnesium (Mg+2) These chemicals are absolutely essential in many bodily functions including fluid balance, nerve conduction, muscle contraction (including the heart), blood clotting and pH balance. Other materials dissolved in plasma are carbohydrates (glucose), cholesterol, hormones and vitamins. Cholesterol is normally transported attached to lipoproteins such as low-density lipoproteins (LDLs) and high-density lipoproteins (HDLs). For more information on cholesterol, read How Cholesterol Works. When plasma is allowed to clot, the fluid left behind is called serum. When blood is collected from a patient it is allowed to clot in a test tube, where the cells and clotting factors fall to the bottom and the serum is left on top. Serum is tested for all the numerous items discussed above to determine if any abnormalities exist. There are four major blood types: A, B, AB, and 0. The blood types are determined by proteins called antigens (also called agglutinogens) on the surface of the RBC. A+: 34 percent A-: 6 percent B+: 9 percent B-: 2 percent AB+: 3 percent AB-: 1 percent O+: 38 percent O-: 7 percent There are two antigens, A and B. If you have the A antigen on the RBC, then you have type A blood. When B antigen is present, you have type B blood. When both A and B antigens are present, you have type AB blood. When neither are present, you have type O blood. When an antigen is present on the RBC, then the opposite antibody (also called agglutinin) is present in the plasma. For instance, type A blood has anti-type-B antibodies. Type B blood has anti-type-A antibodies. Type AB blood has no antibodies in the plasma, and type O blood has both anti-type-A and anti-type-B antibodies in the plasma. These antibodies are not present at birth but are formed spontaneously during infancy and last throughout life. In addition to the ABO blood group system, there is an Rh blood group system. There are many Rh antigens that can be present on the surface of the RBC. The D antigen is the most common Rh antigen. If the D antigen is present, then that blood is Rh+. If the D antigen is missing, then the blood is Rh-. In the United States, 85 percent of the population is Rh+ and 15 percent is Rh-. Unlike in the ABO system, the corresponding antibody to the Rh antigen does not develop spontaneously but only when the Rh- person is exposed to Rh antigen by blood transfusion or during pregnancy. When an Rh- mother is pregnant with an Rh+ fetus, then the mother forms antibodies that can travel through the placenta and cause a disease called hemolytic disease of the newborn (HDN), or erythroblastosis fetalis.

how many base pairs in a gene?

Both genes and genomes come in a variety of sizes. About 1,000 base pairs would be enough DNA to encode most proteins. But introns—"extra" or "nonsense" sequences inside genes—make many genes longer than that. Human genes are commonly around 27,000 base pairs long, and some are up to 2 million base pairs. gene: (in technical use) a distinct sequence of nucleotides forming part of a chromosome, the order of which determines the order of monomers in a polypeptide or nucleic acid molecule which a cell (or virus) may synthesize. how many genes are on a chromosome? Genes are contained in chromosomes, which are in the cell nucleus. A chromosome contains hundreds to thousands of genes. Every normal human cell contains 23 pairs of chromosomes, for a total of 46 chromosomes. A trait is any gene-determined characteristic and is often determined by more than one gene.

Cast iron

Cast iron is a group of iron-carbon alloys with a carbon content greater than 2%. Its usefulness derives from its relatively low melting temperature

icy clathrates

Clathrate is a structure in which water molecules under certain conditions bond to form complex networks of molecules forming cage-like structures that encapsulate a guest molecule, which is a gas.

Kosmotropic

Co-solvents are defined as kosmotropic if they contribute to the stability and structure of water-water interactions. Kosmotropes cause water molecules to favorably interact, which also stabilizes intramolecular interactions in macromolecules such as proteins.

Colobopsis saundersi

Colobopsis saundersi, synonym Camponotus saundersi, is a species of ant found in Malaysia and Brunei, belonging to the genus Colobopsis. A worker can explode suicidally and aggressively as an ultimate act of defense, an ability it has in common with several other species in this genus and a few other insects. When the carpenter ant senses that it is going to lose a fight it gets as close as it can to its enemy, contracts it abdominal muscles really hard, and blows up! Its defensive behaviours include self-destruction by autothysis, a term coined by Maschwitz and Maschwitz (1974). Two oversized, poison-filled mandibular glands run the entire length of the ant's body. When combat takes a turn for the worse, the worker ant violently contracts its abdominal muscles to rupture its gaster at the intersegmental fold, which also bursts the mandibular glands, thereby spraying a sticky secretion in all directions from the anterior region of its head.[4][5] The glue, which also has corrosive properties and functions as a chemical irritant, can entangle and immobilize all nearby victims.

Public domain

Creative work that's not copyrighted and therefore free for you to use whenever you want.

humancentric

Definition of anthropocentric. 1 : considering human beings as the most significant entity of the universe. 2 : interpreting or regarding the world in terms of human values and experiences.

how do atoms release photons?

Each atom has a preferred number of electrons zipping around its nucleus. ... A photon is produced whenever an electron in a higher-than-normal orbit falls back to its normal orbit. During the fall from high energy to normal energy, the electron emits a photon -- a packet of energy -- with very specific characteristics.

fascist vs dictator

Fascism is a form of government that is a type of one-party dictatorship. Fascists are against democracy. They work for a totalitarian one-party state. This aim is to prepare the nation for armed conflict, and to respond to economic difficulties.

trophic structure

Feeding relationships between organisms in a community.

Pioneer species

First species to populate an area during primary succession The Pioneer species are hardy species which are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by fire. Some lichens grow on rocks without soil, so may be among the first of life forms, and break down the rocks into soil for plants.

how many genes are on a chromosome?

Genes are contained in chromosomes, which are in the cell nucleus. A chromosome contains hundreds to thousands of genes. Every normal human cell contains 23 pairs of chromosomes, for a total of 46 chromosomes. A trait is any gene-determined characteristic and is often determined by more than one gene.

What is the oldest Internet meme?

Godwin's Law is one of the oldest and most well-known internet memes that is still relevant today. It is an internet adage, coined by Mike Godwin in 1990 on the Usenet newsgroup discussion board, that says,"As an online discussion grows longer, the probability of a comparison involving Hitler approaches 1."

horsehair worm vs grasshopper

Horsehair worms are insect parasites that belong to the phylum Nematomorpha. One of the most common species in the United States in Gordius robustus. The body of the horsehair worms is extremely long and thread-like. Lengths of a foot or more are not common. The body diameter is about the width of a pencil lead. They are creamy to blackish in color, and frequently are twisted and coiled like a discarded thread. Not much is known about the life of horsehair worms. Adults, the stage most commonly seen, live in water or very moist soil. Adults live in all types of fresh-water habitats and can be found in both temperate and tropical regions. They commonly swim or crawl about with a whip-like motion. Immature stages are parasites on insects or crustaceans living in or near water, or in moist soil. One species of horsehair worm lives in salt water and parasitizes crabs. Beetles, cockroaches, crickets or grasshoppers are the most common hosts in urban areas. Emergence from the host occurs only when the host is near water. Occasionally, horsehair worms are found after a cricket or cockroach is crushed, or when the host hops into a container of water, and the worm exits out of the insect's body. Since horsehair worms are parasitic, they are assumed to be beneficial in the control of certain insects. Its true value as a parasite, however, is questionable because the worm does not kill its host until it matures. Horsehair worms are not parasites of humans or pets. Therefore, these creatures are primarily of interest as one of nature's oddities. If their presence in a swimming pool is bothersome, they can be safely removed by hand or with a net.

RNA World Hypothesis

Hypothesis that describes how the Earth may have been filled with RNA-based life before it became filled with the DNA-based life we see today.

Some of the radio static is from the big bang..

I know nothing of radio astronomy, but I heard that television and radio static are actually the background radiation from the big bang? Some of the static is, the Sun, stars and other objects add to it. So the TV is not tuned to pick up CMB, but it does get a small fraction. When it is detuned from a TV station, the static you get is composed of all sorts of things, including stuff induced from sparks, lightning, stars, and the CMB. Awesome.

abiotic components

In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them underpin all biology. E.g. Temperature, light, water, atmosphere, etc. Abiotic variables found in terrestrial ecosystems can include things like rain, wind, temperature, altitude, soil, pollution, nutrients, pH, types of soil, and sunlight. The boundaries of an individual abiotic factor can be just as unclear as the boundaries of an ecosystem

when did diamonds become popular?

In fact, diamond engagement rings didn't become popular until 1947 when De Beers, the British company that mined diamonds in South Africa, launched an advertising campaign. With the help of Hollywood stars and the slogan, "A diamond is forever," diamond engagement rings skyrocketed in popularity.

differentiation

In geology, igneous differentiation, or magmatic differentiation, is an umbrella term for the various processes by which magmas undergo bulk chemical change during the partial melting process, cooling, emplacement, or eruption. When earth formed all the heavy stuff sunk to the core and the light stuff stayed on the surface

microphylls

In lycophytes, a small leaf with a single unbranched vein. In plant anatomy and evolution a microphyll is a type of plant leaf with one single, unbranched leaf vein. Plants with microphyll leaves occur early in the fossil record, and few such plants exist today. In the classical concept of a microphyll, the leaf vein emerges from the protostele without leaving a leaf gap

nearby supernova trigger nebula to form stars

In some nebulae, stars form out of large clouds of gas and dust; once some stars have formed inside the cloud, their light illuminates the cloud, making it visible to us. These star formation regions are sites of emission and reflection nebulae, like the famous Orion Nebula shown in the picture on the right. Exploding Stars. ... When a star like the Sun dies, it casts its outer layers into space, leaving its hot, dense core to cool over the eons. But some other types of stars expire with titanic explosions, called supernovae. A supernova can shine as brightly as an entire galaxy of billions of "normal" stars.

Isochron dating

Isochron dating uses the fact that inert isotopes of an element have exactly the same chemical properties as their radioactive relatives. Scientists typically determine the age of a rock or meteorite by using the isochron method. For purposes of illustration, consider the rubidium-strontium decay system. In this system, the radioactive parent rubidium-87 (87Rb) decays to the stable daughter isotope strontium-87 (87Sr). Isochron dating is a common technique of radiometric dating and is applied to date certain events, such as crystallization, metamorphism, shock events, and differentiation of precursor melts, in the history of rocks. Isochron dating can be further separated into mineral isochron dating and whole rock isochron dating; both techniques are applied frequently to date terrestrial and also extraterrestrial rocks (meteorites). The advantage of isochron dating as compared to simple radiometric dating techniques is that no assumptions are needed about the initial amount of the daughter nuclide in the radioactive decay sequence. Indeed, the initial amount of the daughter product can be determined using isochron dating. This technique can be applied if the daughter element has at least one stable isotope other than the daughter isotope into which the parent nuclide decays. All forms of isochron dating assume that the source of the rock or rocks contained unknown amounts of both radiogenic and non-radiogenic isotopes of the daughter element, along with some amount of the parent nuclide. Thus, at the moment of crystallization, the ratio of the concentration of the radiogenic isotope of the daughter element to that of the non-radiogenic isotope is some value independent of the concentration of the parent. As time goes on, some amount of the parent decays into the radiogenic isotope of the daughter, increasing the ratio of the concentration of the radiogenic isotope to that of the daughter. The greater the initial concentration of the parent, the greater the concentration of the radiogenic daughter isotope will be at some particular time. Thus, the ratio of the daughter to non-radiogenic isotope will become larger with time, while the ratio of parent to daughter will become smaller. For rocks that start out with a small concentration of the parent, the daughter/non-radiogenic ratio will not change quickly as compared to rocks starting with a large concentration of the parent. An isochron diagram will only give a valid age only if all samples are cogenetic, which means they have the same initial isotopic composition (that is, the rocks are from the same unit, the minerals are from the same rock, etc.), all samples have the same initial isotopic composition (at t0), and the system has remained closed. Isochron dating is useful in the determination of the age of igneous rocks, which have their initial origin in the cooling of liquid magma. It is also useful to determine the time of metamorphism, shock events (such as the consequence of an asteroid impact) and other events depending of the behaviour of the particular isotopic systems under such events. It can be used to determine the age of grains in sedimentary rocks and understand their origin by a method known as a provenance study.

R-selected species

Life history traits maximize reproductive success in uncrowded environments. Many small offspring that mature quickly, little if any parental care. r-selected species are those that emphasize high growth rates, typically exploit less-crowded ecological niches, and produce many offspring, each of which has a relatively low probability of surviving to adulthood (i.e., high r, low K). A typical r species is the dandelion (genus Taraxacum).

What is Lord Kelvin most famous for?

Lord Kelvin (1824-1907) Famous for: Devising the absolute temperature scale, now called the 'Kelvin scale' Formulating the second law of thermodynamics.

The Ordovician Period

Marine algae abundant; colonization of land by diverse fungi, plants, and animals The Ordovician Period lasted almost 45 million years, beginning 488.3 million years ago and ending 443.7 million years ago. * During this period, the area north of the tropics was almost entirely ocean, and most of the world's land was collected into the southern supercontinent Gondwana. The Ordovician-Silurian extinction events, when combined, are the second-largest of the five major extinction events in Earth's history in terms of percentage of genera that became extinct. ... Extinction was global during this period, eliminating 49-60% of marine genera and nearly 85% of marine species.

Oncotic or colloid osmotic pressure

Oncotic or colloid osmotic pressure is a form of osmotic pressure exerted by proteins in the blood plasma or interstitial fluid. Hydrostatic pressure is the force generated by the pressure of fluid within or outside of capillary on the capillary wall.

What forms a nebula?

Other nebulae are regions where new stars are beginning to form. A nebula is a giant cloud of dust and gas in space. Some nebulae (more than one nebula) come from the gas and dust thrown out by the explosion of a dying star, such as a supernova. Other nebulae are regions where new stars are beginning to form. Supernova.

cretaceous period

Period from 144 million to 66 million years ago. Continents move toward their present-day positions as South America splits from Africa. Widespread volcanic activity occurs. First flowering plants appear. Dinosaurs, including Tyrannosaurus rex, dominate. First snakes appear. Mass extinction at the end of the period causes disappearance of many land and marine life forms, including dinosaurs. Cretaceous Period, in geologic time, the last of the three periods of the Mesozoic Era. The Cretaceous began 145.0 million years ago and ended 66 million years ago; it followed the Jurassic Period and was succeeded by the Paleogene Period (the first of the two periods into which the Tertiary Period was divided).

Petrology

Petrology is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology.

radiocarbon calibration

Radiocarbon calibration. ... The term Before Present (BP) is established for reporting dates derived from radiocarbon analysis (where "present" is 1950). Uncorrected dates are stated as "uncal BP", and calibrated (corrected) dates as "cal BP". The cal prefix indicates that the dates are the result of radiocarbon calibration using tree ring data. These values should correspond exactly to normal historical years BC and AD. The term cal BP means the number of years before 1950 and can be directly compared to calendar years.

stochasticity

Random variation; variation happening by chance

Rhenium-osmium dating

Rhenium-Osmium dating is a form of radiometric dating based on the beta decay of the isotope 187Re to 187Os. This normally occurs with a half-life of 41.6 × 109 y,[1] but studies using fully ionised 187Re atoms have found that this can decrease to only 33 y.[2] Both rhenium and osmium are strongly siderophilic (iron loving), while Re is also chalcophilic (sulfur loving) making it useful in dating sulfide ores such as gold and Cu-Ni deposits.

Bird vision

Some birds excellent vision, much better than ours. Owls are adapted to seeing at night, they have huge collections of rod cells that see shapes, sizes, and motion, but not colors (there would be no real point to having a lot of cones, that see colors if you are a night bird. Hawks eyes are adapted to spotting their prey from a distance. Vision and hearing are birds' primary senses, I am not certain of how all species compare to humans. There's probably a lot of variation.

How to calculate the age of the sun?

Stars change over time. We can observe that change, calculate how fast that change is happening, and use that to determine the star's age. Stars work by converting hydrogen to helium. Each unit of hydrogen that changes to helium releases a set quantity of energy. We can look at the star's energy output to figure out how fast the hydrogen is being converted to helium, and look at the ratio of hydrogen to helium to figure out how long that has been happening. It's a bit more complex than that, of course, but that's one way to do it. Imagine you are walking along the street and you see a faucet that is dripping water, and you see a bucket under the faucet that is collecting the water. You can calculate how long the bucket has been sitting there since it was last emptied by measuring how fast water is coming out of the faucet and how much water is in the bucket. Same basic thing. Measure how fast hydrogen is being changed to helium and look to see how much hydrogen and how much helium there is.

Steel

Steel is an alloy of iron and carbon, and sometimes other elements. Because of its high tensile strength and low cost, it is a major component used in buildings, infrastructure, tools, ships, trains, automobiles, machines, appliances, and weapons. Iron is the base metal of steel. Iron is able to take on two crystalline forms (allotropic forms), body centered cubic and face centered cubic, depending on its temperature. In the body-centered cubic arrangement, there is an iron atom in the center and eight atoms at the vertices of each cubic unit cell; in the face-centered cubic, there is one atom at the center of each of the six faces of the cubic unit cell and eight atoms at its vertices. It is the interaction of the allotropes of iron with the alloying elements, primarily carbon, that gives steel and cast iron their range of unique properties. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile, or soft and easily formed. In steel, small amounts of carbon, other elements, and inclusions within the iron act as hardening agents that prevent the movement of dislocations. The carbon in typical steel alloys may contribute up to 2.14% of its weight. Varying the amount of carbon and many other alloying elements, as well as controlling their chemical and physical makeup in the final steel (either as solute elements, or as precipitated phases), slows the movement of those dislocations that make pure iron ductile, and thus controls and enhances its qualities. These qualities include the hardness, quenching behavior, need for annealing, tempering behavior, yield strength, and tensile strength of the resulting steel. The increase in steel's strength compared to pure iron is possible only by reducing iron's ductility.

Stellar chemistry

Stellar chemistry is the study of the chemical composition of astronomical objects; stars in particular, hence the name stellar chemistry. The significance of stellar chemical composition is an open ended question at this point. Some research asserts that a greater abundance of certain elements (such as carbon, sodium, silicon, and magnesium) in the stellar mass are necessary for a star's inner solar system to be habitable over long periods of time. The hypothesis being that the "abundance of these elements make the star cooler and cause it to evolve more slowly, thereby giving planets in its habitable zone more time to develop life as we know it." Stellar abundance of oxygen also appears to be critical to the length of time newly developed planets exist in a habitable zone around their host star.[2] Researchers postulate that if our own sun had a lower abundance of oxygen, the Earth would have ceased to "live" in a habitable zone a billion years ago, long before complex organisms had the opportunity to evolve.

competitive exclusion

Strong competition can lead to local elimination of one of the species. the inevitable elimination from a habitat of one of two different species with identical needs for resources.

Secondary succession

Succession following a disturbance that destroys a community without destroying the soil Secondary succession is one of the two types ecological succession of a plants life. As opposed to the first, primary succession, secondary succession is a process started by an event (e.g. forest fire, harvesting, hurricane, etc.) that reduces an already established ecosystem (e.g. a forest or a wheat field) to a smaller population of species, and as such secondary succession occurs on preexisting soil whereas primary succession usually occurs in a place lacking soil. Many factors can affect secondary succession, such as trophic interaction, initial composition, and competition-colonization trade-offs. The factors that control the increase in abundance of a species during succession may be determined mainly by seed production and dispersal, micro climate; landscape structure (habitat patch size and distance to outside seed sources); bulk density, pH, and soil texture (sand and clay).

the big bounce theory

The Big Bounce is a hypothetical cosmological model for the origin of the known universe. It was originally suggested as a phase of the cyclic model or oscillatory universe interpretation of the Big Bang, where the first cosmological event was the result of the collapse of a previous universe.

Cretaceous-Paleogene extinction event

The Cretaceous-Paleogene extinction event, also known as the Cretaceous-Tertiary extinction, was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago. As originally proposed in 1980 by a team of scientists led by Luis Alvarez and his son Walter Alvarez, it is now generally thought that the K-Pg extinction was caused by the impact of a massive comet or asteroid 10 to 15 km (6 to 9 mi) wide, 66 million years ago, which devastated the global environment. At the end of the Cretaceous Period, 65 million years ago, an asteroid hit Earth in the Yucatan Peninsula, Mexico, forming what is today called the Chicxulub impact crater. ... Whatever its cause, this extinction event marks the end of the Cretaceous Period and of the Mesozoic Era.

Where, when and how did the planet Earth get its water?

The Earth is thought to have had oceans from very early on, at least 4 billion years ago (the Earth is around 4.5 billion years old) and probably earlier. Types of rock called Greenstone, that can only form underwater, have been dated to this old for example. As to how it got the water, there are 2 ideas, and it was probably a mix of both. Outgassing. The Earth will have released lots of gases from its very hot interior, creating its early atmosphere. This will have included water vapor, and also other compounds that might oxidize to create water. Bombardment. There was a period around this time, called the Late Heavy Bombardment, where the Earth was probably hit by large numbers of comets and asteroids. Most of the craters on the Moon date from this period. These comets would have had a lot of water. This period is likely due to Jupiter and Saturn particularly slowly changing their orbits till they finally settled into their current ones. During this period the changes in their orbits may have disrupted the orbits of many comets and asteroids, causing chaos.

Permian-Triassic extinction event

The Permian-Triassic extinction event, also known as the P-Tr extinction, the P-T extinction, the End-Permian Extinction, and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, as well as between the Paleozoic and Mesozoic eras, approximately 252 million years ago. It was a combination of many factors. The main trigger was volcanic activity. *Siberia Map.* The pink there is all lava deposits (the Siberian Traps), spanning several degrees of latitude and all of them deposited at exactly 215 Ma - the time of the Permian-Triassic boundary. That's just a segment of their extent - they cover 1.6 million km², sometimes down to a depth of 3000m. The Traps are made of basalt, so the kind of lava that emerges slowly from fissures (think Iceland), not erupts from volcanoes. This means that this sequence of lava was deposited over a long time, namely 600000 years. Changes were evident from the late Permian, as I detail in the post linked above, but at one point (215 Ma), a critical threshold was reached and the whole biosphere collapsed. This threshold was caused by global warming, which was ultimately caused by this massive volcanism. The temperatures had risen by 6°C (as evidenced by oxygen isotope studies). This increased the ocean's temperatures, slowing down circulation and decreasing the amount of oxygen that can be dissolved, leading to widespread anoxia (lack of oxygen). There was another contributing factor. Carbon isotope studies across the PT boundary show an enormous increase in light carbon isotopes, a drop beyond what we would expect from just volcanism and methane. The other source is gas hydrates buried in the oceans, and released suddenly by earthquakes (which would have been frequent, given the volcanism). All of these - volcanism CO2 and methane, plus the hydrates, pushed the Earth out of the equilibrium zone and caused the whole system to collapse. Global warming led to enormous amounts of acid rain, killing land life both directly and indirectly by washing away all the soil. The ocean anoxia took care of marine life. All because of a couple of degrees. Heh.

runaway greenhouse effect siberia

The Siberian permafrost is a particular danger. A large region called the Yedoma could undergo runaway decomposition once it starts to melt, because microbes in the soil would eat the carbon and produce heat, melting more soil and releasing ever more greenhouse gases The Arctic is warming faster than the rest of the planet, and climatologists have long warned that this will cause positive feedbacks that will speed up climate change further. The region is home to enormous stores of organic carbon, mostly in the form of permafrost soils and icy clathrates that trap methane - a powerful greenhouse gas that could escape into the atmosphere. Clathrate is a structure in which water molecules under certain conditions bond to form complex networks of molecules forming cage-like structures that encapsulate a guest molecule, which is a gas. Would release a heck of a lot of frozen methane.

Triassic-Jurassic extinction event

The Triassic-Jurassic extinction event marks the boundary between the Triassic and Jurassic periods, 201.3 million years ago, and is one of the major extinction events of the Phanerozoic eon, profoundly affecting life on land and in the oceans. In the seas, a whole class and 23-34% of marine genera disappeared The cause of the end-Triassic extinction is a matter of considerable debate. Many scientists contend that this event was caused by climate change and rising sea levels resulting from the sudden release of large amounts of carbon dioxide. Two groups of animals survived the Permian Extinction: Therapsids, which were mammal-like reptiles, and the more reptilian Archosaurs. In the early Triassic, it appeared that the Therapsids would dominate the new era.

collective learning

The ability to share, preserve, and build upon ideas over time. The view that the human species has a unique capacity to accumulate and share complex knowledge and to transmit this knowledge from one generation to the next.

How did we find out the age of Earth?

The age of the Earth is 4.54 ± 0.05 billion years This dating is based on evidence from radiometric age dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples. Following the development of radiometric age dating in the early 20th century, measurements of lead in uranium-rich minerals showed that some were in excess of a billion years old. The oldest such minerals analyzed to date—small crystals of zircon from the Jack Hills of Western Australia—are at least 4.404 billion years old. Comparing the mass and luminosity of the Sun to those of other stars, it appears that the Solar System cannot be much older than those rocks. Calcium-aluminium-rich inclusions—the oldest known solid constituents within meteorites that are formed within the Solar System—are 4.567 billion years old,giving an age for the Solar System and an upper limit for the age of Earth. It is hypothesised that the accretion of Earth began soon after the formation of the calcium-aluminium-rich inclusions and the meteorites. Because the exact amount of time this accretion process took is not yet known, and the predictions from different accretion models range from a few million up to about 100 million years, the exact age of Earth is difficult to determine. It is also difficult to determine the exact age of the oldest rocks on Earth, exposed at the surface, as they are aggregates of minerals of possibly different ages. You also might ask what is radiometric dating? By their chemical nature, rock minerals contain certain elements and not others; but in rocks containing radioactive isotopes, the process of radioactive decay generates exotic elements over time. By measuring the concentration of the stable end product of the decay, coupled with knowledge of the half life and initial concentration of the decaying element, the age of the rock can be calculated. Thus the age of the oldest terrestrial rock gives a minimum for the age of Earth, assuming that no rock has been intact for longer than the Earth itself.

the big rip theory

The belief that the universe, which is expanding at a great and greater speed, will eventually rip apart leaving only energy behind. In physical cosmology, the Big Rip is a hypothetical cosmological model concerning the ultimate fate of the universe, in which the matter of the universe, from stars and galaxies to atoms and subatomic particles, and even spacetime itself, is progressively torn apart by the expansion of the universe at a certain time in the future. According to the standard model of cosmology the scale factor of the universe is known to be accelerating and, in the future era of cosmological constant dominance, will increase exponentially. However, this expansion is similar for every moment of time (hence the exponential law - the expansion of a local volume is the same number of times over the same time interval), and is characterized by an unchanging, small Hubble constant, effectively ignored by any bound material structures. By contrast in the Big Rip scenario the Hubble constant increases to infinity in a finite time.

Canyon Diablo meteorite

The best estimate for Earth's age is based on radiometric dating of fragments from the Canyon Diablo iron meteorite. From the fragments, scientists calculated the relative abundances of elements that formed as radioactive uranium decayed over billions of years. The Canyon Diablo meteorites include the many fragments of the asteroid that created Barringer Crater (Meteor Crater), Arizona, United States. Meteorites have been found around the crater rim, and are named for nearby Canyon Diablo, which lies about three to four miles west of the crater. The asteroid fell about 50,000 years ago.[3] The meteorites have been known and collected since the mid-19th century and were known and used by pre-historic Native Americans. The Barringer Crater, from the late 19th to the mid-20th century, was the center of a long dispute over the origin of craters that showed little evidence of volcanism. That debate was settled in 1960, thanks to Eugene Shoemaker's study of the crater. In 1953, Clair Cameron Patterson measured ratios of the lead isotopes in samples of the meteorite. The result permitted a refinement of the estimate of the age of the Earth to 4.550 billion years (± 70 million years). The biggest fragment ever found is the Holsinger Meteorite, weighing 639 kilograms (1,409 lb), now on display in the Meteor Crater Visitor Center on the rim of the crater. Other famous fragments:

evapotranspiration

The combined amount of evaporation and transpiration Evaporation of water from soil plus transpiration from plants. Correlates with species richness. Evapotranspiration is the sum of evaporation and plant transpiration from the Earth's land and ocean surface to the atmosphere. Evaporation accounts for the movement of water to the air from sources such as the soil, canopy interception, and waterbodies.

Holocene

The current interglaciation period, extending from 10,000 years ago to the present on the geologic time scale. The Holocene Epoch began 12,000 to 11,500 years ago at the close of the Paleolithic Ice Age and continues through today. As Earth entered a warming trend, the glaciers of the late Paleolithic retreated. Tundra gave way to forest.

exudation

The escape of fluid, proteins, and blood cells from the vascular system into the interstitial tissue or body cavities Those unpleasant stains around your armpits — that's an exudation, dude — the release of a bodily liquid through your skin.

Guttation

The exudation of water droplets from leaves, caused by root pressure in certain plants. Guttation is the exudation of drops of xylem sap on the tips or edges of leaves of some vascular plants, such as grasses, and a number of fungi. Guttation is not to be confused with dew, which condenses from the atmosphere onto the plant surface. At night, transpiration usually does not occur, because most plants have their stomata closed. When there is a high soil moisture level, water will enter plant roots, because the water potential of the roots is lower than in the soil solution. The water will accumulate in the plant, creating a slight root pressure. The root pressure forces some water to exude through special leaf tip or edge structures, hydathodes or water glands, forming drops. Root pressure provides the impetus for this flow, rather than transpirational pull. Guttation is most noticeable when transpiration is suppressed and the relative humidity is high, such as during the night. The process of guttation formation in fungi is unknown.

Hadean era

The first 500 million years of Earth's history, when it was hot, bombarded by asteroids and the atmosphere was devoid of oxygen. Earth was living hell. Lava all over the place.

fundamental niche

The full potential range of the physical, chemical, and biological factors a species can use if there is no competition from other species. Fundamental niche is the entire set of conditions under which an animal (population, species) can survive and reproduce itself. Realized niche is the set of conditions actually used by given animal (pop, species), after interactions with other species (predation and especially competition) have been taken into account.

the golden age of astronomy

The idea that since we evolved at a point where dark energy hasn't accelerated the universe too much, we are able to see other cosmic objects which lets us know we are potentially not alone on this ball of stardust.

Globalism

The idea that the world is becoming increasingly interconnected a philosophy which regards the entire world as one giant community that should be unified politically and economically

Platypus can sense electromagnetic fields

The mechanoreceptor allows for physical detection of objects in the water whereas the electroreceptor receives electric stimuli. ... In fact, platypuses can respond to electric fields as low as 20mV per cm in a highly directional manner. So this means when prey moves near a platypus, the platypus can sense individual muscle contractions! My god.

Agrarian society/civilization

The most technologically advanced form of preindustrial society. Members engage primarily in the production of food, but increase their crop yields through technological innovations such as the plow. An agrarian society, or agricultural society, is any community whose economy is based on producing and maintaining crops and farmland. Another way to define an agrarian society is by seeing how much of a nation's total production is in agriculture.

geosphere

The mostly solid, rocky part of the Earth; extends from the center of the core to the surface of the crust. There are several conflicting definitions for geosphere. The geosphere may be taken as the collective name for the lithosphere, the hydrosphere, the cryosphere, and the atmosphere. The different collectives of the geosphere are able to exchange different mass and/or energy fluxes

phosphorus cycle

The movement of phosphorus atoms from rocks through the biosphere and hydrosphere and back to rocks. The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere.

Nematoda

The phylum of roundworms found in aquatic habitats, wet soil, moist tissues of plants, and body fluids of animals

why tobacco plants make nicotine?

The short answer is that tobacco plants make nicotine to discourage insects from eating them (it is poisonous to them), so what one really has to do is make a connection between insects and people. ... Simplifying things a bit, nicotine often acts as a stimulant by making nerves fire more.

rhizosphere

The soil region close to plant roots and characterized by a high level of microbiological activity. The rhizosphere is the narrow region of soil that is directly influenced by root secretions, and associated soil microorganisms known as the root microbiome

character displacement

The tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species. Character displacement is the phenomenon where differences among similar species whose distributions overlap geographically are accentuated in regions where the species co-occur, but are minimized or lost where the species' distributions do not overlap.

What caused the potato famine?

There was no famine in Ireland ..There was plenty of food available to those who could afford it and they were few,those who were poor were allowed to perish like dogs either from starvation or associated disease....Ships loaded with produce left Irish ports under armed guard for England every day. During the worst year of the great starvation in 1847 4000 ships loaded with all sorts of produce sailed for England to feed their masses.The poor souls who perished were set up for destruction in the previous century by the imposition of the penal laws which resulted in the Irish Catholic people losing almost everything . Their land holdings were reduced to almost plots and potatoes were the only nourishing cheap source of food available for them to grow,when the blight hit they were destroyed..Many could not pay their rents so they were evicted from the little hovels they called home and died on the sides of the roads.The British Government were those in charge at the time so i will leave it to the readers to decide who they should cast blame upon for that abominable holocaust in Ireland.

Alcohol origins

Therefore, the theory goes, alcoholism as a disease resulted because the human genome has not had enough time to fully adapt to alcohol. Another model suggests that human ancestors began consuming alcohol as early as 80 million years ago, when early primates occasionally ate rotting fermented fruit rich in ethanol. Animals eat fermented fruit to catch a buzz. This is evident in birds, monkeys, and elephants. That's totally unrefined ethanol. Someone found out that if you eat fermented fruit, you get a buzz. The rest is history. Alcohol consumption became a status symbol for the wealthy, During the Middle Ages, concoctions were distilled to produce spirits. Alcohol has also served as a thirst quencher when water was polluted. In the 1700s, home-brewing processes were replaced by commercially made beer and wine, which became important for the economies of Europe.

homo heidelbergensis

This human species is thought to be ancestral to both Neanderthals and modern humans A transitional species between Homo erectus and Homo sapiens Homo heidelbergensis. This early human species had a very large brow ridge, and a larger braincase and flatter face than older early human species. It was the first early human species to live in colder climates; their short, wide bodies were likely an adaptation to conserving heat.

when trilobites ruled the world

Trilobites disappeared in the mass extinction at the end of the Permian about 252 million years ago. The trilobites were among the most successful of all early animals, existing in oceans for almost 300 million years.

Uranium-lead dating

Uranium-lead dating, abbreviated U-Pb dating, is one of the oldest[1] and most refined of the radiometric dating schemes. It can be used to date rocks that formed and crystallised from about 1 million years to over 4.5 billion years ago with routine precisions in the 0.1-1 percent range. The method is usually applied to zircon. This mineral incorporates uranium and thorium atoms into its crystal structure, but strongly rejects lead when forming. As a result, newly-formed zircon deposits will contain no lead, meaning that any lead found in the mineral is radiogenic. Since the exact rate at which uranium decays into lead is known, the current ratio of lead to uranium in a sample of the mineral can be used to reliably determine its age. The method relies on two separate decay chains, the uranium series from 238U to 206Pb, with a half-life of 4.47 billion years and the actinium series from 235U to 207Pb, with a half-life of 710 million years. Uranium decays to lead via a series of alpha (and beta) decays, in which 238U with daughter nuclides undergo total eight alpha and six beta decays whereas 235U with daughters only experience seven alpha and four beta decays. The existence of two 'parallel' uranium-lead decay routes (238U to 206Pb and 235U to 207Pb) leads to multiple dating techniques within the overall U-Pb system. The term U-Pb dating normally implies the coupled use of both decay schemes in the 'concordia diagram' (see below). However, use of a single decay scheme (usually 238U to 206Pb) leads to the U-Pb isochron dating method, analogous to the rubidium-strontium dating method. Finally, ages can also be determined from the U-Pb system by analysis of Pb isotope ratios alone. This is termed the lead-lead dating method. Clair Cameron Patterson, an American geochemist who pioneered studies of uranium-lead radiometric dating methods, used it to obtain one of the earliest estimates of the age of the Earth.

Can a bite from a Lone Star tick make a person allergic to meat forever, or is the allergy temporary only?

We don't actually know the answer to this question. Some anecdotal reports on individual patients indicate that it may last up to 4 years with diminishing effect. For others, it has lasted longer with no end in sight. But while it is not a factor in Lyme disease, the lone star tick does transmit bacteria that cause several types of illness. Those illnesses include ehrlichiosis; red meat allergy (Alpha-gal syndrome); and Southern Tick-Associated Rash Illness (STARI), which produces rashes similar to those seen with Lyme disease. Alpha-gal syndrome is a recently identified type of food allergy to red meat. In the United States, the condition most often begins when a Lone Star tick bite transmits a sugar molecule called alpha-gal into the body. In some people, this triggers an immune system reaction that later produces mild to severe allergic reactions when they eat red meat. There's no treatment other than avoiding red meat. In alpha-gal syndrome, signs and symptoms typically don't appear for three to six hours after eating red meat. Can be so bad that the fumes from a barbecue will cause issues.

Calculating the age of earth

While there are many independent sources that give you some crude estimate of the age of Earth, Radiometric dating is the most accurate method to put a number on it. The basic principle is that radioactive elements decay into other elements. And they do it very reliably at a constant rate. For example the half-life of Uranium-238 is 4.51 billion years. How did we compute that? Of course no one was around to observe it for that long. Instead, we noticed a pattern in the observations we made today. If you let uranium decay, every year it decays by the same percentage (say x%, for some tiny, yet significantly measurable value of x). This rate is constant for uranium extracted and purified from all sources. The nature of all radioactive elements are the same in this regard. If you know the yearly decay rate, you can find the time it takes to become half the original. We have also measured that some half-lifes are only minutes rather than billions of years. If we know the initial abundance of some material and today's abundance we can calculate the time elapsed in between. Now here is the tricky part. How do we know the composition of something in the past? We make a hypothesis that there was a time when the material solidified from a molten state. (Why is the hypothesis acceptable? We'll come to this later). Now you need to know a little bit of solid state chemistry, which deals with the atomic arrangement of crystalline solids. Here's what a quartz crystal looks like from the outside: The plane surfaces were not crafted artificially. You can find these samples on the field. The reason they have these regular shapes is because there is a periodic arrangement of atoms within it, in this case, it is a repeated arrangement of rhombo-hedral unit-cells, which looks like this: If you melt quartz and let it solidify very slowly, you will grow the same kind of crystal. The reason this happens is because the atoms have certain sizes and directions, and prefer certain bond angles. When solidifying, they try to acquire the least energy state, which results in periodic formations. Also because of the same crystallization process, the material has a very accurate and constant composition ratio. In the case of quartz, it is 1:2 in the number of atoms of silicon to oxygen. If you started with some other impurities or excess silicon in the initial molten state, they would separate out into other crystals and the part that is made of quartz remains of mostly pure composition (Again, this happens due to thermodynamic reasons and the process is very well understood through experimentation today) (*). The slowly you decrease the temperature, the larger will be the individual crystal phases. The minerals we observe in nature have just the patterns we'd expect if they were formed through this process. Now there are some crystals that contain radioactive elements. We know that they start with a precise composition at the time of formation. At that time only the chemical properties of the elements determine crystal shape and size, which are retained. As the element decays over time in the solid state, the by-products are not separated out. They remain locked inside the lattice as defects. Today we can measure the concentration of the original element as well as primary/secondary byproducts etc. and compute the length of time. If you find two minerals right next to each other, and date one of them using uranium-lead decay rate, and the other using samarium-neodymium, it turns out they give the same answer (within measurement accuracy limits), say 913.5 +- 2.2mya and 912.8 +- 1.7 mya. (mya stands for million years ago) which gives you a lot of confidence that it's not merely a coincidence and the minerals crystallized at the same time together (The only way this could trick us is if the decay rates changed harmoniously by keeping the relative rates of all radioactive elements the same). Sometimes, there are pieces of evidence for the age of something other than radioactive. Maybe we know it from geologic patterns, fault lines, the rate of displacement etc. Then using the theory of radiometric dating, we can predict the concentration of radioactive byproducts in the minerals in that region, and the measurements agree very reliably with prediction. This is why it is a accepted scientific method. (*) In some crystals, the ratio composition is not exactly constant. Some kinds of ions may be continuously replaced by a very similar ion. Yet, there exist constraint relationships that lets us infer the missing data from observations today. For Uranium-lead dating, the initial substrate is usually not a pure crystal, but a Zircon crystals with some of the Zirconium ions replaced by Uranium ions. Since these two cations are chemically very similar, they can be interchanged in the lattice in any ratio. But the total amount of this kind of ion is fixed. Lead is chemically very dissimilar to both elements, which means that the crystallization process will reject all lead impurities during formation. After billions of years, we can find the amount of uranium and lead present in the sample to determine the age.

primate vs monkey

Within the suborder of anthropoids, primates are grouped into monkeys, apes and hominids. The easiest way to distinguish monkeys from the other anthropoids is to look for a tail. Most monkey species have tails, but no apes or hominids do. Monkeys are much more like other mammals than apes and humans are.

Wombat

Wombats are short-legged, muscular quadrupedal marsupials that are native to Australia. They are about 1 m in length with small, stubby tails and weigh between 20 and 35 kg. There are three extant species and they are all members of the family Vombatidae.

how much gold is in earth's core?

Wood has calculated that 1.6 quadrillion tons of gold must lie in Earth's core. This may sound like a lot, but it is really only a tiny percentage of the core's overall mass—about one part per million. The core holds six times as much platinum, Wood notes, "but people get less excited about that than gold. Pretty impressive that we even have some gold on the surface considering how dense it is compared to other elements.

Zircon

Zircon is a mineral belonging to the group of nesosilicates. Its chemical name is zirconium silicate, and its corresponding chemical formula is ZrSiO₄ Zirconium is a chemical element with the symbol Zr and atomic number 40. The name zirconium is taken from the name of the mineral zircon, the most important source of zirconium. It is a lustrous, grey-white, strong transition metal that closely resembles hafnium and, to a lesser extent, titanium.

protobiont

a collection of abiotically produced molecules surrounded by a membrane or membrane-like structure An aggregation of organic molecules, surrounded by a membrane, that abiotically coalesces into resemblances of living matter; thought to be the precursors of prokaryotic cells. first forms of life

argyle

a diamond pattern woven or knitted into fabric

TP53 gene

a gene that codes for a protein (P53) that regulates transcription to prevent cancers. Mutations in P53 are associated with many cancers. The TP53 gene provides instructions for making a protein called tumor protein p53 (or p53). This protein acts as a tumor suppressor, which means that it regulates cell division by keeping cells from growing and dividing (proliferating) too fast or in an uncontrolled way. The p53 protein is located in the nucleus of cells throughout the body, where it attaches (binds) directly to DNA. When the DNA in a cell becomes damaged by agents such as toxic chemicals, radiation, or ultraviolet (UV) rays from sunlight, this protein plays a critical role in determining whether the DNA will be repaired or the damaged cell will self-destruct (undergo apoptosis). If the DNA can be repaired, p53 activates other genes to fix the damage. If the DNA cannot be repaired, this protein prevents the cell from dividing and signals it to undergo apoptosis. By stopping cells with mutated or damaged DNA from dividing, p53 helps prevent the development of tumors. Because p53 is essential for regulating cell division and preventing tumor formation, it has been nicknamed the "guardian of the genome."

Potassium-argon dating (K-Ar dating)

a method of dating rocks from the relative proportions of radioactive potassium-40 and its decay product, argon-40. Potassium-argon dating, abbreviated K-Ar dating, is a radiometric dating method used in geochronology and archaeology. It is based on measurement of the product of the radioactive decay of an isotope of potassium (K) into argon (Ar). Potassium is a common element found in many materials, such as micas, clay minerals, tephra, and evaporites. In these materials, the decay product 40Ar is able to escape the liquid (molten) rock, but starts to accumulate when the rock solidifies (recrystallizes). The amount of argon sublimation that occurs is a function of the purity of the sample, the composition of the mother material, and a number of other factors. These factors introduce error limits on the upper and lower bounds of dating, so that final determination of age is reliant on the environmental factors during formation, melting, and exposure to decreased pressure and/or open-air. Time since recrystallization is calculated by measuring the ratio of the amount of 40Ar accumulated to the amount of 40K remaining. The long half-life of 40K allows the method to be used to calculate the absolute age of samples older than a few thousand years.[1] The quickly cooled lavas that make nearly ideal samples for K

Phosphate

a natural mineral containing chemical compounds often used in fertilizers Phosphate is necessary for the formation of bone and teeth. Phosphate is also used as a building block for several important substances, including those used by the cell for energy, cell membranes, and DNA (deoxyribonucleic acid). The body obtains phosphate from foods and excretes it in urine and sometimes stool.

quillworts

a plant related to the club mosses, having a dense rosette of long slender leaves, the bases of which contain the spore-producing organs, and occurring typically as a submerged aquatic. Isoetes, commonly known as the quillworts, is the only extant genus of plants in the family Isoetaceae, which is in the class of lycopods. There are currently 192 recognized species, with a cosmopolitan distribution but with the individual species often scarce to rare

insects

a small arthropod animal that has six legs and generally one or two pairs of wings. Insects or Insecta are hexapod invertebrates and the largest group within the arthropod phylum. Definitions and circumscriptions vary; usually, insects comprise a class within the Arthropoda. As used here, the term Insecta is synonymous with Ectognatha.

anal fissure

a small crack-like sore in the skin of the anus that can cause severe pain during a bowel movement

pyrogen

a substance, typically produced by a bacterium, that produces fever when introduced or released into the blood.

Lithotroph

an organism that uses reduced inorganic compounds as its electron source Lithotrophs are a diverse group of organisms using inorganic substrate to obtain reducing equivalents for use in biosynthesis or energy conservation via aerobic or anaerobic respiration. Lithotrophs are a diverse group of organisms using inorganic substrate (usually of mineral origin) to obtain reducing equivalents for use in biosynthesis (e.g., carbon dioxide fixation) or energy conservation (i.e., ATP production) via aerobic or anaerobic respiration. Examples of lithotrophs include iron-oxidizing bacteria that metabolize reduced iron to oxidized iron, purple sulfur bacteria that transform sulfide into sulfur, nitrifying bacteria that use ammonia and convert it into nitrite or use nitrite to produce nitrate, hydrogen bacteria that oxidize hydrogen to water, and a ...

Radiogenic nuclide

atomic species that are formed by radioactive decay (stable daughter)

cronies

close friends or companions

breakneck

dangerously or extremely fast

John Green is the New York Times bestselling author of Looking for Alaska, An Abundance of Katherines, Paper Towns, The Fault in Our Stars, and Turtles All the Way Down. He is one half of the vlogbrothers on YouTube and co-creator of educational series Crash Course.

dude wrote a bestselling book and made crash course. what.

ecosystem ecology

emphasizes energy flow and chemical cycling among the various biotic and abiotic components Ecosystem ecology is the integrated study of living and non-living components of ecosystems and their interactions within an ecosystem framework. This science examines how ecosystems work and relates this to their components such as chemicals, bedrock, soil, plants, and animals

Nitrate reductase

enzyme that reduces nitrate to nitrite NO3 to NO2 Nitrate reductases are molybdoenzymes that reduce nitrate to nitrite. This reaction is critical for the production of protein in most crop plants, as nitrate is the predominant source of nitrogen in fertilized soils.

Homo habilis

extinct species of upright east African hominid having some advanced humanlike characteristics (man of skill) first to make stone tools It was an important discovery because it enabled this species' arm, leg and body proportions to be determined. These proportions revealed that this Homo habilis was more ape-like than previously believed. Like apes, this individual had relatively long arms and short legs.

detritivores

feed on plant and animal remains and other dead matter Obtain energy from detritus (trash/debris) Detritivores, also known as detrivores, detritophages, detritus feeders, or detritus eaters, are heterotrophs that obtain nutrients by consuming detritus. There are many kinds of invertebrates, vertebrates and plants that carry out coprophagy. There are many examples of detritivores; some of them include millipedes, dung beetles, earthworms, fiddler crabs and sea cucumbers. Earthworms eat decaying plant and animal matter in the soil.

angiosperms

flowering plants a plant that has flowers and produces seeds enclosed within a carpel. The angiosperms are a large group and include herbaceous plants, shrubs, grasses, and most trees. The flowering plants, also known as angiosperms, Angiospermae, Magnoliophyta, or, more colloquially, flowers, are the most diverse group of land plants, with 64 orders, 416 families, approximately 13,000 known genera and 300,000 known species. Like gymnosperms, angiosperms are seed-producing plants.

Piltdown Man

fossil find considered an important link in human evolution until it was shown to be a fake in 1953 The Piltdown Man was a paleoanthropological fraud in which bone fragments were presented as the fossilised remains of a previously unknown early human. The falsity of the hoax was demonstrated in 1953. An extensive scientific review in 2016 established that amateur archaeologist Charles Dawson was its likely perpetrator. In 1912, Charles Dawson claimed that he had discovered the "missing link" between ape and man. In February 1912, Dawson contacted Arthur Smith Woodward, Keeper of Geology at the Natural History Museum, stating he had found a section of a human-like skull in Pleistocene gravel beds near Piltdown, East Sussex.[2] That summer, Dawson and Smith Woodward purportedly discovered more bones and artifacts at the site, which they connected to the same individual. These finds included a jawbone, more skull fragments, a set of teeth, and primitive tools. The Piltdown hoax is prominent for two reasons: the attention it generated around the subject of human evolution, and the length of time, 41 years, that elapsed from its alleged initial discovery to its definitive exposure as a composite forgery.

deposition

gas to solid opposite of sublimation

Graupel

granular snow pellets — called also soft hail

From there, it took a gap of only 66 years for another remarkable aeronautical achievements to happen, which means that the first successful airplane flight and first ever moon landing were separated by less than seven decades. On December 17, 1903, Wilbur and Orville Wright made four brief flights at Kitty Hawk with their first powered aircraft. The Wright brothers had invented the first successful airplane. The Wrights used this stopwatch to time the Kitty Hawk flights. Apollo 11 was the first manned mission to land on the Moon. The first steps by humans on another planetary body were taken by Neil Armstrong and Buzz Aldrin on July 20, 1969. The astronauts also returned to Earth the first samples from another planetary body.

holy crap.

Sonoran Desert

home of the saguaro cactus desert in south Arizona and Mexico

Pig iron

iron with a high carbon content; brittle Pig iron is an intermediate product of the iron industry, also known as crude iron, which is obtained by smelting iron ore in a blast furnace. Pig iron has a very high carbon content, typically 3.8-4.7%,[1] along with silica and other constituents of dross, which makes it very brittle and not useful directly as a material except for limited applications. The traditional shape of the molds used for pig iron ingots was a branching structure formed in sand, with many individual ingots at right angles[3] to a central channel or "runner", resembling a litter of piglets being suckled by a sow. When the metal had cooled and hardened, the smaller ingots (the "pigs") were simply broken from the runner (the "sow"), hence the name "pig iron".[4] As pig iron is intended for remelting, the uneven size of the ingots and the inclusion of small amounts of sand caused only insignificant problems considering the ease of casting and handling them.

brachiopods

lamp shells; resemble clams; dorsal and ventral shells superficially resemble clams and other hinge-shelled molluscs, but the two halves of the shell are dorsal and ventral rather than lateral as in clams

polemics

n. The art of controversy or disputation. the branch of Christian theology devoted to the refutation of errors

obligate mutualism

one species cannot survive without the other An example of obligate mutualism is the relationship between ants and the Acacia plant. The plant provides food for the ant, as well as shelter. In return, the ants defend the plant from other herbivores, or organisms that eat plants, as well as remove other plants from the vicinity of their plant so it can grow better. Another example is the mycorrhizal (pronounced 'my-core-rye-zal') fungi that live on plant roots. The plant roots take advantage of the increased water uptake from the fungi, and the fungi get nutrients from the plant. Another example is the microbiome. Without those little buggers in our stomachs we wouldn't be able to eat half of the stuff that we do.

Anti-fouling paint

or bottom paint, prevents barnacles and other marine organisms from adhering to the hulls of ships. Anti-fouling paint - a category of commercially available underwater hull paints (also known as bottom paints) - is a specialized category of coatings applied as the outer (outboard) layer to the hull of a ship or boat, to slow the growth and/or facilitate detachment of subaquatic organisms that attach to the hull and can affect a vessel's performance and durability (see also biofouling). Anti-fouling paints are often applied as one component of multi-layer coating systems which may have other functions in addition to their antifouling properties, such as acting as a barrier against corrosion on metal hulls that will degrade and weaken the metal, or improving the flow of water past the hull of a fishing vessel or high-performance racing yachts. Fouling on boats will reduce the aerodynamic design of the boat causing up to 30% more fuel to be burned.

abdominal

pertaining to the abdomen

osmotic pressure

pressure that must be applied to prevent osmotic movement across a selectively permeable membrane the pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis, often used to express the concentration of the solution.

coevolution

process in which two or more species evolve in response to changes in each other Another example of beneficial coevolution is the relationship between flowering plants and the respective insect and bird species that pollinate them. In this respect, flowering plants and pollinators have developed co-adaptations that allow flowers to attract pollinators, and insects and birds have developed specialized adaptations for extracting nectar and pollen from the plants (shown below).

apoptosis

programmed cell death

homo neanderthalensis

the species before us homo sapiens; lived form 30,000 to 300,000 years ago; they were stronger and had bigger brains Neanderthals, alternatively spelt as "Neandertals", are an extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago. They went extinct probably by competition or extermination by immigrating modern humans, great climatic change, disease, or some combination

physical cosmology

the study of the structure and history of the universe Physical cosmology is a branch of cosmology concerned with the studies of the largest-scale structures and dynamics of the universe and with fundamental questions about its origin, structure, evolution, and ultimate fate.

4 crop rotation

the system of growing a different crop in a field each year to preserve the fertility (mineral content) of the land -Rice, Soybeans, Sweet Potatoes, Corn. -This crop rotation increases nitrogen in the soil with the use of legumes to keep land productive The sequence of four crops (wheat, turnips, barley and clover), included a fodder crop and a grazing crop, allowing livestock to be bred year-round. The four-field crop rotation became a key development in the British Agricultural Revolution.

oxygen holocaust

time when single-celled bacteria adapted to photosynthesize and release oxygen thus killing all anaerobic bacteria, which could not live in an oxygen-rich environment A chronology of oxygen accumulation suggests that free oxygen was first produced by prokaryotic and then later by eukaryotic organisms in the ocean. These organisms carried out photosynthesis more efficiently,[compared to?] producing oxygen as a waste product.[7][8] In one interpretation, the first oxygen-producing cyanobacteria could have arisen before the GOE,[7][9] from 2.7-2.4 Ga and perhaps even earlier. However, oxygenic photosynthesis also produces organic carbon that must be segregated from oxygen to allow oxygen accumulation in the surface environment, otherwise the oxygen back-reacts with the organic carbon and does not accumulate. Occurred: 2,300 million years ago

TNF

tumor necrosis factor Tumor necrosis factor (TNF) superfamily composes of a group of cytokines and their receptors which can reduce cell death (apoptosis). This superfamily is composed of 19 ligands and 29 receptors in humans. TNFα and Lymphotoxin-alpha (LTα) is first identified members of the family. TNF is a pro-inflammatory cytokine that was identified over 4 decades ago as the factor induced by lipopolysaccharide (LPS) that causes apoptosis and necrosis (cell death) of several cancer cell lines and the regression of some cancers in experimental animal models. The factor was isolated as a 17 kDa polypeptide that in its active state is a homotrimer. TNF is important for immunity and inflammation, and is part of the host response to bacteria, viruses and cancers. Local increases of TNF around sites of injury induce cardinal signs of inflammation, which include heat, swelling, pain and redness. Initially used to treat cancers, in some systems TNF can promote tumor progression. While there are many problems associated with systemic high dose treatment with TNF, recent evidence has demonstrated that local administration in conjunction with interferon γ (IFNγ), promotes the regression of adenomas and melanomas in patients due to apoptosis of the angiogenic endothelium.

Late Devonian extinction

unclear why so many aquatic species died, might have been lack of oxygen 360 million years ago; temperatures drop, ocean layers dropped; ocean anoxia; plants caused cooling The Late Devonian extinction was one of five major extinction events in the history of life on Earth. A major extinction, the Kellwasser event, occurred at the boundary that marks the beginning of the last phase of the Devonian period, the Famennian faunal stage, about 376-360 million years ago A variety of causes have been proposed for the Devonian mass extinctions. These include asteroid impacts, global anoxia (widespread dissolved oxygen shortages), plate tectonics, sea level changes and climatic change. Placoderms, for example, did not survive, acanthodians were decimated, and almost all agnathans vanished. Numerous brachiopods became extinct, conodonts all but disappeared, and only one family of trilobites survived. In total, over 70% of species living in the Devonian no longer existed in the Carboniferous Period.

Aposematism

warning coloration bright conspicuous markings of certain distasteful or poisonous animals, which predators recognize and learn to avoid

Henry Walter Bates

was an English naturalist and explorer who gave the first scientific account of mimicry in animals. He was most famous for his expedition to the rainforests of the Amazon with Alfred Russel Wallace, starting in 1848. Wallace returned in 1852, but lost his collection on the return voyage when his ship caught fire. When Bates arrived home in 1859 after a full eleven years, he had sent back over 14,712 species (mostly of insects) of which 8,000 were new to science. Bates wrote up his findings in his best-known work, The Naturalist on the River Amazons.

"Change is the only constant."

/

Very often the success of one species must come at the expense of another.

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bench scale

A small scale version of a larger project. It serves as a way to prototype a process before you build it full scale

myriapods

A terrestrial arthropod with many body segments and one or two pairs of legs per segment. millipedes and centipedes comprise the two classes of living myriapods.

globalization

Actions or processes that involve the entire world and result in making something worldwide in scope. the process by which businesses or other organizations develop international influence or start operating on an international scale.

devonian period

Age of Fishes

alpha-gal allergy

Alpha-gal allergy, also known as meat allergy or mammalian meat allergy (MMA), is a reaction to galactose-alpha-1,3-galactose (alpha-gal), whereby the body is overloaded with immunoglobulin E (IgE) antibodies on contact with the carbohydrate. Lone Star tick causes it

how many synapses in the brain

Each individual neuron can form thousands of links with other neurons in this way, giving a typical brain well over 100 trillion synapses (up to 1,000 trillion, by some estimates). Functionally related neurons connect to each other to form neural networks (also known as neural nets or assemblies). 86 billion neurons

Eris is larger than pluto

Eris's mass is about 0.27% of the Earth mass, about 27% more than dwarf planet Pluto, although Pluto is slightly larger by volume. ... Because Eris appeared to be larger than Pluto, NASA initially described it as the Solar System's tenth planet. Eris is the furthest dwarf planet from the Sun, and is also the most massive currently recognized dwarf planet. Eris is located beyond the orbit of Neptune and beyond the Kuiper belt in a region known as the "scattered disc". Not planets since they don't have enough gravity to clear their own orbits of debris Discovered January 5, 2005

transpiration

Evaporation of water from the leaves of a plant Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. The remaining 97-99.5% is lost by transpiration and guttation. Used as a cooling mechanism

congealed

Frozen; solidified Turned from liquid to solid

galvanic corrosion on boats

Galvanic corrosion is the process that can cause the hull of your boat to start to corrode when you are connected to shore power. Corrosion occurs when two dissimilar metals are immersed in a conductive solution (sea water) and are electrically connected (by the shore connection). Boats will use sacrificial anodes for this reason. The electrons that make up that current are supplied by one of the metals giving up bits of itself — in the form of metal ions — to the seawater. ... This piece of metal is called a sacrificial anode, and most often it is zinc. In fact, most boaters refer to sacrificial anodes simply as zincs. E.g. you have a steel hull and a aluminum propeller

Galvanization

Galvanization or galvanizing is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerged in a bath of molten zinc.

Ammonium

NH4+ It is a solution of ammonia in water. Ammonium hydroxide is used as a cleaning agent and sanitizer in many household and industrial cleaners. Ammonium hydroxide is also used in the manufacture of products such as fertilizer, plastic, rayon and rubber. Produced by mixing ammonia with water

nitrogen is triple bonded

Nitrogen is a diatomic molecule in the VA family on the periodic table. Nitrogen has five valence electrons, so it needs three more valence electrons to complete its octet. A nitrogen atom can fill its octet by sharing three electrons with another nitrogen atom, forming three covalent bonds, a so-called triple bond.

Samarium-neodymium dating

Samarium-neodymium dating is a radiometric dating method useful for determining the ages of rocks and meteorites, based on the radioactive decay of a long-lived samarium isotope (147Sm) to a radiogenic neodymium isotope (143Nd). Neodymium isotope ratios together with samarium-neodymium ratios are used to provide information on age information and the source of igneous melts. It is sometimes assumed that at the moment when crustal material is formed from the mantle the neodymium isotope ratio depends only on the time when this event occurred, but thereafter it evolves in a way that depends on the new ratio of samarium to neodymium in the crustal material, which will be different from the ratio in the mantle material. Samarium-neodymium dating allows us to determine when the crustal material was formed. The usefulness of Sm-Nd dating stems from the fact that these two elements are rare earth elements and are thus, theoretically, not particularly susceptible to partitioning during sedimentation and diagenesis. Fractional crystallisation of felsic minerals changes the Sm/Nd ratio of the resultant materials. This, in turn, influences the rate at which the 143Nd/144Nd ratio increases due to production of radiogenic 143Nd.

K-selected species

Species that produce a few, often fairly large offspring but invest a great deal of time and energy to ensure that most of those offspring reach reproductive age.

Ordovician-Silurian extinction events

The Ordovician-Silurian extinction events, when combined, are the second-largest of the five major extinction events in Earth's history in terms of percentage of genera that became extinct. All of the major animal groups of the Ordovician oceans survived, including trilobites, brachiopods, corals, crinoids and graptolites, but each lost important members. Widespread families of trilobites disappeared and graptolites came close to total extinction. Around 443 million years ago, 85% of all species on Earth went extinct in the Ordovician-Silurian extinction. The extinction was a most likely a result of global cooling and reduced sea levels, which dramatically impacted the many marine species living in warm, shallow coastal waters.

gatekeeping

When someone takes it upon themselves to decide who does or does not have access or rights to a community or identity. "Oh man, I love Harry Potter. I am such a geek!" "Hardly. Talk to me when you're into theoretical physics."

why does your heart beat fast when you pee?

When your bladder is full, your blood pressure and heart rate are higher. When you empty your bladder during urination, your blood pressure and heart rate drop. This drop causes your blood vessels to widen, or dilate. Blood moves more slowly in dilated blood vessels, so it can pool in your legs.

Wrought iron

Wrought iron is an iron alloy with a very low carbon (less than 0.08%) content in contrast to cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag inclusions (up to 2% by weight), which gives it a "grain" resembling wood that is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile, corrosion-resistant and easily welded.

Zirconium

Zirconium is a chemical element with the symbol Zr and atomic number 40. The name zirconium is taken from the name of the mineral zircon, the most important source of zirconium. It is a lustrous, grey-white, strong transition metal that closely resembles hafnium and, to a lesser extent, titanium.

How does homosexuality arise in certain species?

The short answer is that coding attraction to the opposite sex into the genome reliably is hard, and greater reliability incurs a higher cost. Reproductive disadvantages of homosexuality incur a cost as well, and if the latter does not outweigh the former, homosexuality arises. Homosexuality (and more frequently bisexuality) has been documented in many species (see Bagemihl, 2000: Animal Homosexuality and Natural Diversity.) More specifically, there are various hypotheses on evolutionary advantages of alleles that lead to increased probability of homosexuality. A study by Hoskins, Richie and Bailey (2015) found that for fruit flies, the same allele that is responsible for homosexuality in males leads to greater fertility in females. (Presumably, it increases the attraction to males in both sexes.) This effect can outweigh the cost of homosexuality for the fruit flies. In humans, a similar mechanism is known: female relatives of homosexual men tend to have more children, probably because both have stronger feminine traits. The alleles that code for sexual orientation control numerous other factors as well, which may also compensate for the reproductive disadvantage of the individual in other ways than greater benefits for the opposite sex: "Homosexuality is god's way to ensure that the truly gifted are not burdened with children."

soil saturation

The water content of a soil beyond which no more water is absorbed Saturation is the soil water content when all pores are filled with water. The water content in the soil at saturation is equal to the percent porosity. Field capacity is the soil water content after the soil has been saturated and allowed to drain freely for about 24 to 48 hours.

warbler

Various Passeriformes (perching birds) are commonly referred to as warblers. They are not necessarily closely related to one another, but share some characteristics, such as being fairly small, vocal, and insectivorous. They are mostly brownish or dull greenish in color. The New World warblers or wood-warblers are a group of small, often colorful, passerine birds that make up the family Parulidae and are restricted to the New World. They are not closely related to Old World warblers or Australian warblers.

standard candle

an object for which we have some means of knowing its true luminosity, so that we can use its apparent brightness to determine its distance with the luminosity-distance formula In astronomy, a standard candle is a class of objects whose distances can be computed by comparing their observed brightness with their known luminosity. Cepheid variable stars are useful as standard candles because their pulsation period is related to their luminosity in a known way.

water runoff

excess water that flows over the land when the soil is saturated (no more water can be infiltrated)